Stack-seaming mandrel.



A. W. SMITH.

STACK SEAMING MANDREL.

APPLICATION FILED APR. 19, 1915.

1,170,355. Patented Feb. 1, 1916.

J0 Fig.4.

ARTHUR SMITH, or furnace, new our.

STACK-SEAMING MANDREI.

Specification of Letters Patent.

Patented Feb. 1, 1916 Application filed April 19, 1915. Serial No. 22,353.

improvements in stack seaming mandrels.

The primary object of the invention is to provide a mandrel upon which metal stack lengths may be firmly held and seamed by a single workman for either square or round pipes and including elbows thus making it possible for a single man to perform -the work which usually employs three or four men to complete.

A further object of the invention is the provision of a stack forming mandrel adapted for making metal ventilating and heating stacks as well as stove pipes and partition pipes for furnaces and greatly reducing the expense of manufacturing the same.

A still further object is the provision of a stack mandrel being formed adjustable for accommodating stack lengths of differentdimensions and having a clamping device for holding the metal while the side seam of the stack is being quickly double seamed upon the mandrel by a single workman employed in making the stack.

lVith these general objects in view and others that will appear as the nature of the invention is better understood, the same consists in the novel combination and arrangement of parts hereinafter fully described, illustrated in the accompanying drawings and pointed out in the appended claims.

In the drawings forming a part of this application and in which like designating characters refer to corresponding parts throughout the several views: Figure 1 is a side elevation of the device partially broken away and secured to a bench, a stack length being illustrated as clamped upon the mandrel and shown in vertical longitudinal section. Fig. 2 is a top plan view thereof with 'parts broken away and the stack length shown in horizontal longitudinal section. Fig. 3 is an elevational view of the clamp upon the work with the mandrel shown in transverse section and parts being broken away, and Fig. 4 is a sectional view of the completed seam.

It will be understood that the stacks contemplated by this invention such as furnace heating pipes are formed seamed in lengths up to eight feet long being formed of sheet metal such as galvanized iron which are thereafter attached together in longitudinal alinement in the assembled stackformation. A mandrel is now designed whereby a single-workman may rapidly complete the formation of stack lengths, the device consisting essentially of the mandrel 10 ofv I- beam form removably' and adjustably secured to a bench 11 or other stationary support by means of a collar bracket 12 at- ;justed position by means of opposite set boltsl.

A form around which the metal is bent into its stack form is provided upon the mandrel and the same is herein illustrated in connection with the forming of a stack length 15 which is rectangular in cross section. A desired number ofpairs of positioning arms 16 are provided upon the mandrel and being slidably mounted through rectangular transverse openings 17 positioned centrally through the web 18 thereof, it being understood that the said arms are rectangular in cross section and are provided with clamping positioning collars 19. slidably mounted upon the arms and adapted to be retained in the desired adjustment flatly engaging the opposite faces of the mandrel web 18 by means of set screws 20 carried by thesaid collars. Arms 16 are preferablyv ar ranged in pairs, two, pairs 'thereof being herein illustrated and have anvils 21 at their opposite outer ends. The sheet metal 15 being in ther'form of a strip before the same is bent into its stack formation is bent around the anvils 21 engaging the outer flat faces 22'thereof, while the stack length is formed of the desired dimensions by the proper adjustment of the anvil arms16.

It being'understood that the adjacent longitudinal edgesof the sheet metal are overturned and positioned in interlocking engagement after the usual manner of forming a a s n rengag ng P i are P sitioned flatly upon the outer face of one of the mandrel flanges 28, the seam portion being positioned directly over the central longitudinal groove 24: of such flange. A clamp is arranged having a handle 25 to which an angular shank 26 is pivoted as at 27, while spaced curved inclosing jaws 28 are provided upon the shank for slidably mounting the clamp upon the mandrel flange. The handle 25 has a terminal foot 2%) for engaging the sheet metal and retaining the same in fiat contact with the flange face when the said handle is shifted to a position substantially perpendicular to the mandrel. By this arrangement it will be seen that the sheet metal will be clamped to the mandrel when formed as a stacklength and with its seam portion 30 in alinement with the adjacent groove 24 and whereupon the workman with the aid of the proper tools, such as a wooden mallet, may lightly pound upon the clamped metal thus forcing the seam portion thereof in place in the groove 24. The metal clamp is preferably positioned at a point upon the mandrel adjacent the free end thereof and the seam pounding operation is begun at the end of the length adj acent the bench and continues until the complete seam is formed within the mandrel groove 2%, and the stack length or section is then complete and ready tobe assembled.

a stack length will be at once apparent as well as the clamping of the metal upon the mandrel and the formation of the longitudinal locking seam therein by means of the mandrel groove 24 and whereby asingle workman may readily and quickly form the desired size of stack length or unit.

While the form of the invention herein shown and described is what is believed to be the preferred embodiment thereof, it is nevertheless to be understood that minor changes may be made in the form, proportion and details of construction without departing from the spirit and scope of the invention as set forth in the appended claims.

WVhat is claimed as new is 1. A stack forming device comprising an adj ustably mounted mandrel of I-beam form having central longitudinal seam forming grooves upon the outer faces of the base flanges thereof, and adjustably mounted anvils carried by the mandrel web.

2.' A stack forming device comprising an adj ustably mounted mandrel of I-beam form Gopies of this patent may be obtained for having central longitudinal seam forming grooves upon the outer faces of the base flanges thereof, longitudinally shiftable parallel arms transversely carried by the web of the said mandrel, flat faced forming anvils upon the opposite outer ends of the said arms.

3. A stack forming device comprising an adjustably mounted mandrel of I-beam form having central longitudinal sea-m forming grooves upon the outer faces of the base flanges thereof, longitudinally shiftable parallel arms transversely carried by the web of the said mandrel, flat faced forming anvils upon the opposite outer ends of the said arms, the outer end of the said mandrel being rounded and a sheet metal clamp slidably mounted upon one of the base flanges ofthe mandrel.

4. A stack forming device comprising a rigidly mounted collar bracket, a mandrel bar I-shaped in cross section slidably mounted within the said bracket, adjusting screws for said mandrel carried by the bracket, the said mandrel having the free end thereof rounded and its opposite base flanges pro vided with central longitudinal seam forming grooves.

5. A stack forming device comprising a rigidly mounted collar bracket, a mandrel bar I-shaped in cross section slidably mounted within the said bracket, adjusting screws for said mandrel carried by the bracket, the said mandrel having the free tnd thereof rounded and its opposite base flangesprovided with central longitudinal seam forming grooves, and the web of said mandrel having rectangular perforations therethrough, arms arranged in pairs within the said perforations and being formed rectangular in cross section, positioning collars adjustably mounted upon said arms at opposite sides of the mandrel web, forming anvils upon the outer ends of the said arms having outer fiat engaging faces.

6. A device of the class described comprising a mandrel, adjustable anvil forms carried thereby and adapted for receiving sheet metal bent thereover encircling the mandrel, the said mandrel being provided with opposite longitudinal seam forming grooves adapted for the forcible reception of the interlocked'free edges of the sheet metal and sheet metal clamping means carried by the mandrel.

In testimony whereof I afiix my signature.

ARTHUR W. SMITH.

five cents each, by addressing the Commissioner of Patents. Washington. D. C. 

